Synergistic effect of cross-linked carbon nanosheet frameworks and Sb on the enhancement of sodium storage performances

As an anode material for sodium-ion batteries (SIBs), antimony (Sb) has attracted significant interest due to its high theoretical specific capacity. However, it suffers from a huge volume change during the sodiation-desodiation process that leads to poor cyclability. Herein, cross-linked carbon nanosheet frameworks (CCNFs) and Sb nanoparticles (NPs) were combined to construct a high-performance anode material for SIBs. In this composite, Sb nanoparticles were tightly anchored on the carbon frameworks; this provided enhanced structural stability to Sb and prevented the agglomeration during the charge-discharge process. Sb provides a high specific capacity, and the carbon frameworks ensure structural integrity and conductive networks. Moreover, due to this synergistic effect, the as-prepared Sb/CCNFs composite exhibits an excellent cycle stability and rate performances. Considering both the capacity and rate property, the overall performances of the obtained Sb/CCNFs reach the highest level in comparison with those of the reported Sb/C composites. The reversible (charge) capacity can remain 549.3 mA h g after 100 cycles at a current density of 100 mA g. Moreover, a superior rate performance is observed as the reversible capacity still reaches 318 mA h g at a high current density of 3200 mA g. Therefore, this study proposes an effective methodology to improve the key performances of the SIB anode.